28722478 has 4 divisors (see below), whose sum is σ = 43083720. Its totient is φ = 14361238.

The previous prime is 28722443. The next prime is 28722479. The reversal of 28722478 is 87422782.

It is a semiprime because it is the product of two primes.

It is a self number, because there is not a number n which added to its sum of digits gives 28722478.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28722479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7180618 + ... + 7180621.

It is an arithmetic number, because the mean of its divisors is an integer number (10770930).

Almost surely, 2^28722478 is an apocalyptic number.

28722478 is a deficient number, since it is larger than the sum of its proper divisors (14361242).

28722478 is a wasteful number, since it uses less digits than its factorization.

28722478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14361241.

The product of its digits is 100352, while the sum is 40.

The square root of 28722478 is about 5359.3355931496. The cubic root of 28722478 is about 306.2484987848.

The spelling of 28722478 in words is "twenty-eight million, seven hundred twenty-two thousand, four hundred seventy-eight".